function [ H ] = MockHA2B2C( t )

    [T, Y] = ode45(@rigid, t, [1 0 0]);

    H = Y';

end

function dy = rigid(t, y)
    dy = zeros(3,1);    % a column vector
    k1 = 1;
    k2 = 0.5;
    k3 = 1;
    
    dy(1) = - k1*y(1);
    dy(2) = k1*y(1) - k2*y(2);
    dy(3) = k2*y(2);
end